Owens CM, Aurora P, Stanojevic S et al.; London Cystic Fibrosis Collaboration.
Great Ormond Street Hospital, London, UK.
Thorax 2011;66:481–8.
Editor’s note: The lung clearance index (LCI), derived from multiple-breath washout (MBW), is a feasible measure of lung function across the entire pediatric age range. It assesses the evenness of ventilation distribution within the lung, and is a more sensitive tool to detect early lung involvement in patients with cystic fibrosis (CF) than flow-based measures, such as spirometry. A previous retrospective analysis has demonstrated a strong correlation between LCI and structural changes on high-resolution computed tomography (HRCT) scans (Thorax 2008;63:129–34). The use of MBW as a screening tool to detect structural lung damage is attractive, as it avoids the radiation-related risks associated with HRCT. To date, the relationship between LCI and structural lung damage, in comparison to other measures of lung function, has not been studied prospectively.